Kate Middleton's U.S. kin

Prince William's fiancee Kate Middleton, shown in a Dec. 15, 2006, photo, has some family ties to famous Americans, including the first U.S. president, according to The New England Historic Genealogical Society in Boston.

Gilbert Stuart's portrait of George Washington. Kate Middleton is an eighth cousin eight times removed to Washington, the Revolutionary War general and first U.S. president. Their common ancestor, Sir William Gascoigne, died in 1487.

Middleton's other American relatives include explorer Meriwether Lewis, seen here at left, who teamed with William Clark, right, for their renowned 19th-century Western expedition. He's a ninth cousin seven times removed.

Prince William and Kate Middleton pose for photographs in the State Apartments of St James Palace on November 16, 2010, in London. According to the society, Prince William and Middleton are 15th cousins, through Sir Thomas Fairfax, who died during Henry VIII's reign.